We plan to focus on several important unresolved anatomical and physiological problems in an effort to better understand extrageniculate visual processing in the cat. Specifically, we proposed to continue and extend our electrophysiological mapping studies in order to provide a detailed retinotopic map of the extrageniculate visual thalamus. We also proposed a series of anatomical studies aimed at revealing detailed connectivity patterns among retinotopically defined cortical, thalamic, and other subcortical visual centers. These anatomical studies will utilize autoradiographic and HRP methods as well as recording methods to guide the placement of injections in thalamus and cortex. We believe this research will contribute importantly to our understanding of information flow through the mammalian visual system, and further that it will help to parcellate the cat extrageniculate visual thalamus into functional areas.